package org.mikeliu.exp1.exp1;

import java.util.Scanner;

public class Exp1 {
	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		int grade=scanner.nextInt();
		if(grade>=0 && grade <60) {
			System.out.println("不及格");
		}
		else if (grade>=60 && grade<70) {
			System.out.println("及格");
		}
		else if (grade>=70 && grade<80) {
			System.out.println("中");
		}
		else if (grade>=80 && grade<90) {
			System.out.println("良");
		}
		else if (grade>=90 && grade<=100) {
			System.out.println("优");
		}
		else {
			System.out.println("成绩不正确");
		}
		scanner.close();
	}
}
